Single Responsibility Principle (SRP)

Overview

A class should have only one reason to change.

Every module, class, or function should have responsibility over a single part of functionality. If you can describe what a class does using "AND", it has too many responsibilities.

When to Use

• Creating any new class, module, or service
• Adding methods to existing classes
• Reviewing code that "does multiple things"
• Feeling pressure to "just add it here"

The Iron Rule